The present invention relates generally to textile processing apparatus adapted for developing a suede-like finish on a textile fabric and relates more particularly to a sueding arrangement for incorporation in a fabric-forming machine, such as a textile warp knitting machine.
In the textile industry, it is known to finish certain woven and warp knitted fabrics by abrading one or both surfaces of the fabric using a sandpaper or similarly abrasive material to cut and raise constituent surface yarns in the fabric into a closely raised nap producing a soft, smooth surface texture resembling suede leather. This operation, commonly referred to as sueding or sanding, is conventionally performed by a specialized fabric sueding machine wherein the fabric is passed under considerable tension over one or more finishing rolls covered with sandpaper or a similarly abrasive material which are rotated rapidly in the same direction as the fabric travels.
While conventional sueding operations produce satisfactory results in fabrics finished in this manner, several significant disadvantages of conventional sueding equipment detract from its desirability and economy. The relatively high rotational speeds at which the abrasive rolls of conventional sueding machines operate necessarily causes a substantial amount of fibrous lint and fly, fabric finish, abrasive dust and the like to be released from the fabric and the abrasive rolls, some of which may tend to become airborne posing a health hazard to machine operators, some of which may tend to become embedded in the interstices of the fabric detracting from its surface finish, and some of which may tend to accumulate on the abrasive surface of the finishing rolls tending to negate at least somewhat their abrasive sueding effect. To attempt to minimize these problems, conventional sueding machines are typically provided with relatively substantial suction-operated filtering arrangements for withdrawing liberated debris from the regions of the sueding rolls. Even so, the accumulation of debris on the sueding rolls generally occurs rapidly enough that it is commonly necessary to change the sandpaper or abrasive surface material on the rolls for every individual roll of fabric processed.
Additionally, conventional sueding machines are typically limited in their operational widths to the processing of fabrics no greater on average than 60 to 65 inches in width. In most conventional sueding machines, a nip roller or nose bar or another similar mechanical component is employed to hold the fabric against the rotating periphery of the sueding rolls along the full length of each roll and, accordingly, it is highly important that the sueding roll as well as the nip roll or nose bar be very true cylindrically to achieve uniform engagement and sueding effect along the full length of the sueding roll. As will thus be understood, it is highly impractical from an engineering design standpoint to utilize a sueding roll much greater in length than now conventional because the centrifugal forces present at the high rotational speeds at which such rolls operate together with the increased weight of a longer roll would naturally tend to cause deflection of the roll from a true cylindrical configuration as well as being more difficult to balance properly to minimize rotational vibration of the roll. On the other hand, many conventional weaving and warp knitting machines are available for producing fabrics in widths two to three times or more greater in width than the effective operating width of conventional sueding equipment. For example, warp knitting machinery currently in use is capable of producing warp knitted fabrics of 126 inches to 168 inches in width. Conventional weaving machines capable of producing fabrics of comparable widths are also available. Thus, when it is desired to produce a suede finish on fabrics of such greater widths than the maximum widthwise finishing capability of sueding machines, it is necessary to initially cut the fabric lengthwise into at least two smaller width lengths which are then individually processed through a sueding machine.